1. Field of the Invention
This invention relates to anchoring devices and particularly to anchoring devices which are intended to be installed in concrete or other relatively hard material.
2. Description of the Prior Art
The installation of expandable anchors and toggle bolts in concrete floors, walls, roof decks, beams, precast panels, and the like, is well known in the art as a means for anchoring machinery, supporting fixtures, and the like.
U.S. Pat. No. 1,570,439 provides a so-called "seam" anchor bent end portion which is inserted into a hole formed in the joint between two bricks. A bearing block is used to wedge the anchor in the hole. This patent, however, provides no teaching for an anchor adapted for an angled hole.
U.S. Pat. No. 2,691,293 also illustrates an anchor with a curved lower end which is intended to be embedded in place in the concrete when poured. This anchor provides an exposed portion which is threaded for attachment of devices to be anchored. However, the anchor is not removable or reusable or adapted for installation in an angled hole or for use after the concrete is hardened or set.
Useful additional background information is found in a manual entitled "Anchor and Fastener Training Manual for the Building and Construction Trade" published in 1966 by the U.S. Expansion Bolt Company, York, Pa. 17405. However, none of the anchoring devices and anchoring techniques shown in this manual relate to a removable and reusable anchor adapted for installation in an angled hole.
Numerous problems and deficiencies are experienced with conventional anchors and their method of employment in predrilled holes. Conventional anchors are often difficult to seal. Consequently, exposure to water penetration into the hole followed by freezing and thawing often causes deterioration or crumbling of the concrete and may eventually cause the anchor to fail in service. Also, vibration is often associated with slow crumbling and abrading of the concrete by the conventional anchor. In this situation, the conventional anchor may begin to rotate in a hole enlarged by wobbly rotation and failure of the anchor may then occur. In the case of expansion-type anchors which are not properly sealed, the anchor and surrounding concrete sometimes fail and pull out because of a loose-fit in a deteriorated wall surrounding the hole in which the anchor is installed.
Another problem arises with conventional anchors when it is desired to locate an anchor in an exact location and such location interferes with a reinforcing rod, piping, or the like, embedded in the concrete at such location. Vertical drilling for placement of an anchor is impossible and the location must be changed.
From the foregoing, it can be seen that it would be desirable to have a removable and reusable anchor and a method of installing such an anchor based on using a hole angled in the concrete for receiving the secured portion of the anchor. Further, it would be desirable to overcome the deficiencies mentioned above with respect to conventional anchors. The anchor and method of the present invention is, thus, intended to overcome such deficiencies as its primary object. Other objects will appear as the description proceeds.